In "The Stolen Party", by Liliana Heker, the story closes referring to "an infinitely delicate balance."
The character, Rosaura, is caught off guard when the party's hostess, Sefiora Ines offers her money. With her hand extended, thinking that she is about to receive a yo-yo and bracelet, Rosaura presses against her mother when offered money. Rosaura, a cold look bearing down on Ines, freezes.
Ines, aware that she has crossed a line, knows not what to do. She, as frozen as Rosaura, is afraid to move. She is fearful that she moves, she will "shatter an infinitely delicate balance."
What is meant here is that, to this point, Rosaura has not looked at herself as the child of a cleaning-woman. Instead, the societal class lines for her were not distinguished yet. It is not until Ines offers her the money that she realizes she is not, and will never be, of her class. Rosaura's identity is in jeopardy of being shattered, just like the delicate balance between the tow standing together.